A GP needs to give you a referal to a psychiatrist.
You may be able to see a councellor/psychologist and they can refer you?
Where I am, it is fairly simple. We can pretty much got to any doc we can without referal. It costs us the consult fees if we don't have insurance.
Some pdocs take 3 months for an opening, while others are not as busy and free within a few days. But getting a dx, a pdoc you trust, and getting started on the trial and error of meds, needs to happen asap.

Please try and get to sleep. I trust you are in a career where you will be moitored and possibly have a friend to confide in. Look after yourself and rather try sleep before you get out of control. Or you can get to an ER, and a psychiatrist will be forced to help you - you need to consider this option if you are going to hurt yourself or others.